.container {
  max-width: 800px;
  margin: 2rem auto;
  padding: 1rem;
}

.upload-area input {
  display: none;
}

.upload-box {
  border: 2px dashed #1890ff;
  border-radius: 8px;
  padding: 2rem;
  text-align: center;
  cursor: pointer;
  background: #f5fbff;
  transition: all 0.3s;
}

.upload-box:hover {
  background: #e6f7ff;
  transform: translateY(-2px);
}

.error-alert {
  padding: 1rem;
  background: #fff1f0;
  border: 1px solid #ffccc7; 
  border-radius: 4px;
  color: #ff4d4f;
  margin: 1rem 0;
}

.toolbar {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
}

.toolbar input {
  flex: 1;
  padding: 0.5rem;
  border: 1px solid #ddd;
  border-radius: 4px;
}

.toolbar button {
  padding: 0.5rem 1rem;
  background: #1890ff;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

.content-area {
  display: flex;
  border: 1px solid #eee;
  border-radius: 4px;
  background: white;
}

.line-numbers {
  padding: 1rem;
  background: #fafafa;
  border-right: 1px solid #eee;
  color: #666;
  text-align: right;
  user-select: none;
}

.text-content {
  flex: 1;
  padding: 1rem;
  margin: 0;
  overflow: auto;
  max-height: 60vh;
  white-space: pre-wrap;
  line-height: 1.6;
}

.line {
  padding: 2px 0;
}

mark {
  background: #fff566;
  padding: 0 2px;
}